Drug Absorption Kinetics in Goldfish

An equation describing the time course and variability in uptake and toxicity of narcotic chemicals to fish

“…Hydrophobic chemicals of large KO, values tend to have high water-phase resistances rW KO, and accumulate more slowly. This formulation was originally proposed for systems of this type by Yalkowsky et al [25] and is essentially the earlier two-resistance-in-series or "two-film" concept.…”

Solubility of Hydrocortisone in Organic and Aqueous Media: Evidence for Regular Solution Behavior in Apolar Solvents

“…An example is regular solution theory as proposed by Scathard (1) and Hildebrand (2), which is premised on all intermolecular association being of a nonorientating variety. Although this theory has on occasion been overextended to solvent systems where this fundamental assumption is not true, valid applications have provided basic understanding of solubility behavior for various pharmaceutical systems (3)(4)(5)(6)(7)(8).…”

Temperature and Surfactant Dependence of Accumulation of 4-Aminoantipyrine and Ethanol in Fish

“…The accumulation rate of substances toxic to fish has been characterized by measuring the time required for fish to turn over or to die (e.g., [3][4][5][6][7]. This approach requires no chemical analysis, and it is useful for detection of the relative absorption rates of compounds that elicit the end-point.…”

“…For example, an equilibrium model was used recently as the basis for an accelerated test to predict the extent of accumulation of xenobiotics (8). The equilibrium has also been used to model time-for-overturn and time-for-death data (6,7,9). For many compounds studied, the accumulation process appears t o be represented adequately as a simple equilibrium.…”

“…A problem associated with the use of absorption and exsorption rate constants for characterizing accumulation is that the rate constants reflect not only the permeability of barriers to absorption but also the volumes of the fish and bathing solution (7). T o overcome this problem, the equilibrium model was modified so that the accumulation process is characterized by two pharmacokinetic constants: a clearance constant, k, that reflects only the permeability of barriers to absorption and exsorption, and a volume of distribution, V , that reflects the capacity for accumulation.…”